My 2009 Chevy Aveo 5 with automatic transmission has an issue that started today; on the way home on the freeway, the HOLD light started flashing. I noticed later that the coolant temperature gauge was below "C" as if the engine was ice cold.
What could be causing this?
Maybe related: A few weeks ago I was low on coolant; I topped it off and have driven without issue until today. I do have occasional electrical issues, such as the dashboard clock resetting to 01:00 occasionally when the car is off.
I was able to run real-time OBD thanks to GdD's answer, and coolant got up to 138° F after a ten minute drive, and temperature gauge on dashboard still at "C" so likely wiring/sensor. Also got a pending code of "P0128 Coolant Thermostat Malfunction"